title: Inter-hospital variability in post-cardiac arrest mortality.
abstract: OBJECTIVE
  A growing body of evidence suggests that variability in post-cardiac arrest care contributes to differential outcomes of patients with initial return of spontaneous circulation after cardiac arrest. We examined hospital-level variation in mortality of patients admitted to United States intensive care units (ICUs) with a diagnosis of cardiac arrest.
  
  
  METHODS
  Patients with a primary ICU admission diagnosis of cardiac arrest were identified in the 2002--2005 Acute Physiology and Chronic Health Evaluation (APACHE) IV dataset, a multicenter clinical registry of ICU patients.
  
  
  RESULTS
  We identified 4674 patients from 39 hospitals. The median number of annual patients was 33 per hospital (range: 12-116). Mean APACHE score was 94 (+/-38), and overall mortality was 56.8%. Age, severity of illness (acute physiology score), and admission Glasgow Coma Scale were all associated with increased mortality (p<0.001). There was no survival difference for patients admitted from the emergency department vs. the inpatient floor. Among institutions, unadjusted in-hospital mortality ranged from 41% to 81%. After adjusting for age and severity of illness, institutional mortality ranged from 46% to 68%. Patients treated at higher volume centers were significantly less likely to die in the hospital.
  
  
  CONCLUSIONS
  We demonstrate hospital-level variation in severity adjusted mortality among patients admitted to the ICU after cardiac arrest. We identify a volume-outcome relationship showing lower mortality among patients admitted to ICUs that treat a high volume of post-cardiac arrest patients. Prospective studies should identify hospital-level and patient care factors that contribute to post-cardiac arrest survival.
authors.affiliation: The Robert Wood Johnson Clinical Scholars Program, University of Pennsylvania School of Medicine (UPENN SOM), USA. Brendan.Carr@uphs.upenn.edu
authors.forename: Brendan G
authors.initials: BG
authors.lastname: Carr
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Kahn
authors.forename: Raina M
authors.initials: RM
authors.lastname: Merchant
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Kramer
authors.forename: Robert W
authors.initials: RW
authors.lastname: Neumar
mesh_terms: D018806:APACHE; D000368:Aged; D015331:Cohort Studies; D003422:Critical Care / Q000706:statistics & numerical data*; D005260:Female; D006323:Heart Arrest / Q000401:mortality* / Q000628:therapy*; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D020379:Risk Adjustment; D014481:United States / Q000453:epidemiology